Thanks both! Mostly confirms my thoughts.
I probably should have mentioned, my GF does have M&S status and keeping it isn't too hard. Annoyingly we got close to Elite Plus once but didn't make it, and the TK cabin upgrade certs might have been a useful perk on an SFO-IST flight. Oh well...
But redeeming miles and the TK award charts have definitely been less favorable. (At least with OZ I've had decent luck with a few *A upgrade awards, and their award chart has been decent but OZ is picky with US cards and I couldn't actually book a recent award ticket...)
So, I guess where I'm at:
- TK should be easy for me to maintain
- TK won't help as much for earning on LH/LX PE routes (upcoming trip would likely be an LX N fare which is 0% on TK... though I have had luck with switching the mileage program at the LX/LH lounge when this happened once where I credited to UA...)
- TK's award chart has mixed value, but there are some decent options, like potential UA flights
- UA Gold would definitely be more useful for me locally, but probably harder to maintain
- Highly SFO specific, but the Maple Leaf Lounge works with *A Gold, but specifically not UA Gold—and they usually have a barista and/or a good mezcal Negroni.
- Getting lifetime UA status for require moving more international flying to UA, which isn't a problem but other *A partners have better PE and upgrade deals. It's also a stretch.
The easy answer is to credit to UA, not over think things and not encourage extra upgrades/etc. Or not care so much about status! But who am I kidding? I love playing the game.